本节介绍ExecProcNodeFirst函数和ExecProcNode函数。

ExecProcNodeFirst函数

//src/backend/executor/execProcnode.c


static TupleTableSlot *
ExecProcNodeFirst(PlanState *node)
{
	
	check_stack_depth();
	
	
	if (node->instrument)
		node->ExecProcNode = ExecProcNodeInstr;
	else
		node->ExecProcNode = node->ExecProcNodeReal;

	return node->ExecProcNode(node);
}

ExecProcNode函数

//src/include/executor/executor.h

static inline TupleTableSlot *
ExecProcNode(PlanState *node)
{
	if (node->chgParam != NULL) 
		ExecReScan(node);		

	return node->ExecProcNode(node);
}